Several methods for the association of the intact human erythrocyte MN-glycoprotein with phospholipid bilayers such as detergent solubilization followed by dialysis and solvent solubilization, among others, will be refined. The resulting complex will be characterized by a variety of physico-chemical methods such as those used to characterize the hydrophobic peptide-T(is) complex. Particular attention will be given to the detection and close examination of intramembranous particles by freeze-fracture electron microscopy. In addition the hydrophobic peptide T(is)-phospholipid association will be further examined by cross-linking T(is) after it is associated with the membrane in an attempt to determine the stoichiometry of multimer formation. The complex resulting from incorporation of large amounts of T(is) into phospholipid bilayers will be examined by low angle X-ray diffraction to detect the location and orientation of T(is) in the bilayer. BIBLIOGRAPHIC REFERENCES: Segrest, J.P., Pownall, H.J., Jackson, R.L., Glenner, G.G. and Pollock, P.S.: Amyloid A: Amphipathic helixes and lipid binding. Biochemistry 15, 3187 (1976). Segrest, J.P.: Amphipathic helixes and plasma lipoproteins: Thermodynamic and Geometric Considerations. Chem. Phys. Lipids, 18 (1977).